C++ (Cpp) arb_get_interval_fmpz_2exp Examples

Example #1

File: t-get_interval_fmpz_2exp.c Project: isuruf/arb

int main()
{
    slong iter;
    flint_rand_t state;

    flint_printf("get_interval_fmpz_2exp....");
    fflush(stdout);
    flint_randinit(state);

    for (iter = 0; iter < 100000; iter++)
    {
        arb_t x;
        arf_t y;
        fmpz_t a, b, exp;

        arb_init(x);
        arf_init(y);
        fmpz_init(a);
        fmpz_init(b);
        fmpz_init(exp);

        arb_randtest(x, state, 200, 10);

        arb_get_interval_fmpz_2exp(a, b, exp, x);

        arf_set_fmpz_2exp(y, a, exp);
        if (!arb_contains_arf(x, y))
        {
            flint_printf("FAIL:\n\n");
            flint_printf("x = "); arb_print(x); flint_printf("\n\n");
            flint_printf("a = "); fmpz_print(a);
            flint_printf(" exp = "); fmpz_print(exp); flint_printf("\n\n");
            abort();
        }

        arf_set_fmpz_2exp(y, b, exp);
        if (!arb_contains_arf(x, y))
        {
            flint_printf("FAIL:\n\n");
            flint_printf("x = "); arb_print(x); flint_printf("\n\n");
            flint_printf("b = "); fmpz_print(b);
            flint_printf(" exp = "); fmpz_print(exp); flint_printf("\n\n");
            abort();
        }

        arb_clear(x);
        arf_clear(y);
        fmpz_clear(a);
        fmpz_clear(b);
        fmpz_clear(exp);
    }

    flint_randclear(state);
    flint_cleanup();
    flint_printf("PASS\n");
    return EXIT_SUCCESS;
}

Example #2

File: get_unique_fmpz.c Project: argriffing/arb

int
arb_get_unique_fmpz(fmpz_t z, const arb_t x)
{
    if (!arb_is_finite(x))
    {
        return 0;
    }
    else if (arb_is_exact(x))
    {
        /* x = b*2^e, e >= 0 */
        if (arf_is_int(arb_midref(x)))
        {
            /* arf_get_fmpz aborts on overflow */
            arf_get_fmpz(z, arb_midref(x), ARF_RND_DOWN);
            return 1;
        }
        else
        {
            return 0;
        }
    }
    /* if the radius is >= 1, there are at least two integers */
    else if (mag_cmp_2exp_si(arb_radref(x), 0) >= 0)
    {
        return 0;
    }
    /* there are 0 or 1 integers if the radius is < 1 */
    else
    {
        fmpz_t a, b, exp;
        int res;

        /* if the midpoint is exactly an integer, it is what we want */
        if (arf_is_int(arb_midref(x)))
        {
            /* arf_get_fmpz aborts on overflow */
            arf_get_fmpz(z, arb_midref(x), ARF_RND_DOWN);
            return 1;
        }

        fmpz_init(a);
        fmpz_init(b);
        fmpz_init(exp);

        /* if the radius is tiny, it can't be an integer */
        arf_bot(a, arb_midref(x));

        if (fmpz_cmp(a, MAG_EXPREF(arb_radref(x))) > 0)
        {
            res = 0;
        }
        else
        {
            arb_get_interval_fmpz_2exp(a, b, exp, x);

            if (COEFF_IS_MPZ(*exp))
            {
                flint_printf("arb_get_unique_fmpz: input too large\n");
                abort();
            }

            if (*exp >= 0)
            {
                res = fmpz_equal(a, b);

                if (res)
                {
                    fmpz_mul_2exp(a, a, *exp);
                    fmpz_mul_2exp(b, b, *exp);
                }
            }
            else
            {
                fmpz_cdiv_q_2exp(a, a, -(*exp));
                fmpz_fdiv_q_2exp(b, b, -(*exp));
                res = fmpz_equal(a, b);
            }

            if (res)
                fmpz_set(z, a);
        }

        fmpz_clear(a);
        fmpz_clear(b);
        fmpz_clear(exp);

        return res;
    }
}